[Source: Scott Craven, Arizona Republic] -- Midway around a curve the tram comes to a stop. Visitors listen to the twitter of birds on the desert slope before a voice comes over the intercom. "And to your left is the original entrance," the female voice says. "Just beyond the fence." Few would agree with the term "entrance." It's far too grand for a crack in the ground that is barely visible even if you know exactly where to look. In fact, only two people gave it more than a passing notice in the centuries people roamed these hills in the Sonoran Desert about 50 miles southeast of Tucson.
And that discovery in 1974 by spelunkers Randy Tufts and Gary Tenen would lead to an underground labyrinth that now attracts visitors from all over the world. The tram hums back to life and continues to a more tourist-friendly entrance to Kartchner Caverns. Visitors hop out for the short walk to the vaultlike door set into the cliff of the Whetstone Mountains. Beyond it is the man-made tunnel leading to one of the world's most incredible sights. Thousands trek each year to this park south of Benson to tour its intricate underground world. [Note: To read the full article, click here.]